AfA_OS requires some OS3.9 components (Setpatch, icon.library, workbench.library) in WB3.1 to work fully. Using Setpatch which activates these 2 libraries results in WB trying to find the default icon from ENV:Sys when using "AddIcon" within Dopus 4. Thanks for SnoopDOS ! So i just copied all the def-icons from OS3.9 to the corresponding directory of my WB3.1 installation. Hurrah!